Rotating self-locking actuator

Abstract

A rotating self-locking actuator includes a housing, a self-locking device, and a motor shaft at least one end of which extends out of the housing. The self-locking device includes a pin rod, a friction cap which is disposed outside the housing and sleeved over the motor shaft, and an arc-shaped groove extending helically about an axial direction of the motor shaft and provided on a side wall of the friction cap. The pin rod rotates synchronously with the motor shaft and is sliding-fitted with the arc-shaped groove. The motor shaft causes the pin rod to rotate such that the friction cap is driven by the pin rod to move axially to contact the housing, whereby friction self-locking is enabled, and the friction cap is driven by the pin to move axially to detach from the housing, whereby the friction self-locking is released.

We claim: 
     
       1. A rotating self-locking actuator, comprising:
 a housing, 
 a self-locking device, and 
 a motor shaft at least one end of which extends out of the housing, wherein the self-locking device comprises;
 a pin rod; 
 a friction cap which is disposed outside the housing and sleeved over the motor shaft; and 
 an arc-shaped groove extending helically about an axial direction of the motor shaft, the arc-shaped groove being provided on a side wall of the friction cap; 
 
 
       wherein:
 the pin rod rotates synchronously with the motor shaft and is sliding-fitted with the arc-shaped groove; and 
 the motor shaft causes the pin rod to rotate such that the friction cap is driven by the pin rod to move axially to contact the housing, thereby friction self-locking is enabled, and the friction cap is driven by the pin to move axially to detach from the housing, thereby the friction self-locking is released. 
 
     
     
       2. The self-locking actuator of  claim 1 , wherein a through-hole running radially is provided on the motor shaft, the pin rod being insertion-fitted with the through-hole. 
     
     
       3. The self-locking actuator of  claim 1 , wherein a bushing is sleeved over the motor shaft, the bushing rotating synchronously with the motor shaft, the pin rod being fixed on the bushing. 
     
     
       4. The self-locking actuator of  claim 1 , wherein a mounting hole is provided on the friction cap, the mounting hole being in communication with the arc-shaped groove, the pin rod being inserted in the arc-shaped groove via the mounting hole. 
     
     
       5. The self-locking actuator of  claim 1 , wherein the friction cap comprises a cap body where the arc-shaped groove is provided, and support blocks circumferentially provided at intervals at an outer peripheral side of the cap body, the support blocks each having a friction surface for contact with the housing. 
     
     
       6. The self-locking actuator of  claim 5 , wherein the support blocks are U-shaped elastic blocks, bottom edges of the U-shaped elastic blocks contacting the housing to enable friction self-locking. 
     
     
       7. The self-locking actuator of  claim 1 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       8. The self-locking actuator of  claim 1 , wherein an axial distance H between two ends of the arc-shaped groove along the axial direction of the motor shaft is greater than 0 mm and less than 0.5 mm. 
     
     
       9. The self-locking actuator of  claim 1 , wherein two arc-shaped grooves are symmetrically distributed on the side wall of the friction cap. 
     
     
       10. The self-locking actuator of  claim 1 , wherein the actuator comprises an electric motor, the housing comprising a motor housing, at least one end of the motor shaft extends out of the motor housing, and the friction cap moves axially to contact the motor housing, whereby friction self-locking or detachment is enabled; or, the actuator comprises an electric motor and a gearbox, the housing comprises a motor housing and a gearbox housing, at least one end of the motor shaft extends out of the motor housing, and the friction cap moves axially to contact the gearbox housing, whereby friction self-locking or detachment is enabled. 
     
     
       11. The self-locking actuator of  claim 2 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       12. The self-locking actuator of  claim 3 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       13. The self-locking actuator of  claim 4 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       14. The self-locking actuator of  claim 5 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       15. The self-locking actuator of  claim 6 , wherein the arc-shaped groove has a central angle α ranging from 30° to 150°. 
     
     
       16. The self-locking actuator of  claim 1 , wherein the housing comprises (i) a front end cover and (ii) a front bearing disposed on the front end cover.